Effects of subsidence and transplanted trees on soil arbuscular mycorrhizal fungal diversity in a coal mining area of the Loess Plateau

摘要

Arbuscular mycorrhizal fungi (AMF) plays a key role in enhancing resistance to plant stress and diseases, thus improving soil structure. To better understand the effects of coal mining subsidence and mining-after transplanted trees on soil AMF diversity, this study, using spore isolation as well as identification and high-throughput sequencing techniques, analysed the AMF composition and diversity and its correlation with soil factors from three areas—namely, the original undisturbed area (C), mining-after naturally restoring area (S), and post-subsidence artificially planted 6-year-restoring areas (S1, S2, S3, S4). The results showed significant differences in the AMF diversity of the rhizosphere and non-rhizosphere soil in the coal mining subsidence area. Furthermore, transplanted trees affected the soil TN, AP, and TP nutrients. A total of 15 species from four families and seven genera of AMF were isolated and identified from soil samples in the study areas. The relative abundances of these AMF species were: Glomus (59.83–92.57%), Diversispora (0.59–32.73%), Scutellospora (0.59–7.1%), and others (0–0.05%). The most abundant species were Glomus-lamellosu-VTX00193 (3.65–22.64%), followed by Glomus-viscosum-VTX00063 (1.57–7.58%), Glomus-MO-G18-VTX00064 (0.59–10.93%), and Glomus-perpusillum-VTX00287 (0.62–19.47%). Among them, 13 and 15 species in four families from seven genera were isolated from non-rhizosphere and rhizosphere soil of the transplanted tree species, respectively. The morphological diversity and molecular diversity in C were significantly higher than those in S. Further, the AMF diversity in S3 was higher than that in S. TN, AK, and WC were the most influential soil environmental factors for the AMF community structure in the rhizosphere and non-rhizosphere soil samples of each transplanted tree species. This study found that subsidence exerts unique effects on soil properties, and transplanted trees improved the soil properties and promoted an increase in soil AMF community diversity within the study area, S3 promoted the recovery of morphological and molecular diversity. S2 showed increased species diversity and abundance of dominant species. Therefore, the transplanted shrub mixed forests and Hippophae rhamnoides forests exhibited the most significant effects.